Water-heater.



E. S. STACK.

WATER HEATER.

APPLICATION FILED MAY 29,1912.

E ,Zf/. Patented Jan. 19, 1,915.

" 1l'I ST EINER S. STACK, OF SOMEEVIIJ'IJE, MASSACHUSETTS, ASSIG'NOR, BYMESE ASSGN- MEN'IS, TG STACK HEATER 'TION 0F ,MASSACHUSETTS COMPANY, OFIBOSTGN, MASSACHUSETTS, A CORA- WATERiI-IETER.

Speei-cation of Letters Patent.

Application led May 2'9, 1912. Serial No. 700,441.

To all 'whom it may concern Be it known that I, ELMER S. STACK., acitizen of the United States, and. resident of Somerville, in the countyof Middlesex and State of Massachusetts, have invented certain new anduseful Improvements in Water-Heaters, of which the following is aspecification.

This invention relates to a water heater for domestic use. i

My purpose is to provide an improved heater of this general descriptionby which heat may be more rapidly imparted to water than by otherheaters for like purposes, and in which the heating of water torelatively high temperature may be accomplished either continuously orintermittently with a high degree of fuel economy.

have accomplished these objects in a heater having the essential partsand constructed substantially as hereinafter described and as shown inthe drawings accompanyin this application.

In the rawings, Figure 1 represents a. side elevation of an improvedheater embodying my invention with the inclosing case and burner shownin section. Fig. 2 is a cross section of the same on line 2-2 of Fig. 1.Fig.- 3 is a longitudinal section of the heater with parts thereofbroken away.

The same reference characters indicate the same parts in all thefigures.

e heater consists essentially of a collection of tubes of which the endsare connected in headers 1 and 2, the former of which is preferablyvertically above the latter. The cold water to be heated enters thelower. header through a pipe 3, and is distributed to the tubes, throughwhich 1t Hows to the upper header and in which it is heated, and the hotwater passes through the u per header and out through the outlet tu e 4.Each header is constructed pref erably as shown in Fig. 3 and consistsof a conical body having a nipple 5 at its apex and an opening in itsbase. rIhe boundarles of such opening are threaded and a cap 6 isadjustably screwed into engagement with these threads. The caps arecentrally apertured and threaded to connect with the 1ntake and outletpipes respectively. The nipples 5 ofthe headers are threaded to connectwith a central pipe 7 which leads Qm the lower to 'the upper header.

En the conical sides of both headers are numerous openings arrangedpreferably in parallel circular series, the urpose of which is toreceive the ends. ci) tubes, of which there are two or more sets orseries. lIn the embodiment of the invention here represented there arethree such sets of tubes, those of the inner set being designated 8, ofthe intermediate set 9, and of the outer set 10. Their opposite ends aresecured in' their upper and lower headers respectively in a manner whichI will presently describe. The arrangement is such that each set formsin effect an envelop surrounding the central tube approximately coaxiallbut having relatively wide openings, namely the spaces between adjacenttubes of the series, through which the heated products of combustion maypass freely. l

As will be seen best from Fig. 1, the tubes of the enveloping series arenot parallel with the axis of the header, or in other words, they do notpass straight from one header to the other. Instead, their ends areapproximately normal to the surface of the header in which they aresecured, and at a short distance from their ends the tubes are benttoward the axis and at the same time inclined in such a way that eachtube makes an acute and veryv small angle with the plane passing throughthe axis of the header and the point at which said tube is joined tosuch header. Thus the ends of each tube are somewhat off-set from oneanother angularly about the axis of the heater,

Y as appears from Fig. l, but the angle of olfset is relatively smalland is much less than one complete turn. The tubes are in edect sectionsof helices of steep pitch.

In the embodiment shown, the tubes of the outer series or` envelop areinclined downwardly to the right, that is, the tubes nearest to theobserver are so inclined; the tubes of Athe intermediate series areinclined from right to left, that is, oppositely to the outer tubes, andthe tubes of the innermost series are inclined from left to right, thatis, in the same sense as the outer but oppositely to the intermediatetubes. Thereby the tubes of successive circular series cross each other,all the tubes of each series are separated from each other bylongitudinal spaces, and the different series are sepa'- rated byannular spaces, so that the heatingagent may pass freely around andbetween them.

The heater thus described is placed in an upright position in a case 12,into the bottom of which the tube 3 enters and out of ythe top of whichthe tube 4 passes. This case has a base 13 adapted t0 rest on a table,shelf, etc., and in one side it has a door 14: adapted to bey opened togive access to the heater. `Heat is generated within the casing belowthe heater by combustion of gas which is supplied by a burner 15, thelatter being of any suitable character. The heated products ofcombustion rise and flow around and among the tubes. Such of the hotgases as pass within the inner series of tubes strike a bailie plate 16which surrounds the central tube 7 and crosses the innermost annularspace. These gases are checked and caused to pass outwardly across thetubes again. The gases passing between vthe heater and the case engagean' external annular battle 17 which crosses the space between the wallsof the case and the tubes at the upper end of the heater, and arethereby deflected inwardly into Contact with the tubes before they canescape through the annular space between the inner edge of this bailleand the upper header.

It will be seen that owing to the arrangement of the tubes and to thebaffle plates or deflectors 16 and 17, there are no straightuninterrupted passages through which the hot gases may pass, but thatinstead the gases are caused by the baffles to follow paths which arecrossed by the tubes. The tendency of the hot gas is to rise, but beforerising far from the burner it comes into contact with the outwardlybulged lower ends of the tubes. Rising farther it is deflected by theinclined portions of the outer tubes into contact with the oppositelyinclined inner tubes. In this way the hot gas is continually obstructedand caused to circulate into contact with all of the tubes, heating themall uniformly and equally. Practically all the available heat is therebygiven 'to the water in the heater. At the same time, however, the tubesare so nearly straight that the path of the water is almost the shortestpossible and therefore a rapid flow of water through the heater ispermitted. I have found that this arrangement of tubes, in which thepath of the water '1s short and the water is brought constantly intoArenewed thermal contact with the hot gas, gives exceedinglysatisfactory results as to efficiency and economy of fuel consumptionand the rapidity with which a given quantity of water may be brought toa given temperature.

Another feature of importance in a heater ofthis particular constructionis the wa in which the tubes are secured in the hea ers. This is shownin Fig. 3, from which it will be seen that the holes inthe headersthrough which the ends of the tubes pass are smaller than the greatestdiameter of the tubes, and that the ends are reduced so as to passthrough the holes. This reduction of the end provides a shoulder 18 nearthe end of the tube which shoulder bears on the rim of the hole outsideof the header. The extreme end of the tube within the header is flangedover at 19. The shoulder and flange grip the wall of the header betweenthem and secure the end of the tube against any movement relatively tothe header. Each end of every tube is thus secured, and is firm andimmovable regardless of any distortion which may take place in any otherpartof the tube. As all the tubes are curved between their ends, freeplay is afforded for expansion and contraction due to heating andcooling.

I claim:

1. A heater comprising essentially, separated headers and tubes incommunication with said headers, the tubes being bent outward betweentheir ends and inclined with respect to an axial plane of the heater,making less than a complete turn about such ax1s.

2. A heater comprising a plurality of series of tubes for conducting the'fluid to be heated, and a source of heat below said tubes, the tubes ofone series being inclined with respect to the path in which the hotgases issuing from the heater tend to travel, and at an oppositeinclination to the tubes of another series.

3. A heater comprising two headers arranged practically one aboveanother, and tubes connected at opposite ends with said headers and soinclined that the lower end of each is off-set to one side of a lineextending vertically from the point at which its upper end is connectedto the upper header, the tube making a very small acute angle with thevertical.

4. A heater comprising headers arranged in line, and a plurality ofconcentric series of tubes connected at their opposite ends to therespective headers, the tubes of one series being off-set oppositely tothe tubesI of another series from one end to the other.

5. A heater comprising a pair of conical headers in axial alinement withtheir apexes toward each other, and tubes extending from one header tothe other, such tubes being bent near their ends, and arranged so thatsuch ends extend perpendicularly toward conical faces of therespectively adjacent headers.

6. A heater comprising headers of conical form arranged in alinementwith their apexes turned toward each other, a substantially straighttube connected to the apexes of the headers in communication with theinterior thereof, and tubes arranged in a Y plurality of concentricseries around the central tube, connected at their ends to therespective headers, and inclined with respect to lines parallel to theaxis.

7 The combination of a case, a burner in the lower part of said case, aheater above said burner consisting of a central tube, upper and lowerheaders connected to said central tube, inner and outer tubes arrangedin a plurality of concentric series around said central tube, a baillecrossing the inner space between the central tube and inner series ofconcentric tubes, and a baiile between the case and outer series ofconcentric tubes.

8. A heater comprising headers of conical form arranged in alinementwith their apexes turned toward each other, a substantially straightcentral heat-conducting member connected to the apexes of the headers,and tubes arranged in a plurality of concentric series around saidcentral member, connected at their ends to the respective head#- ers,and inclined oppositely to tubes of other series with respect to linesparallel to the axis. v

9. The combination of a case, a burner in the lower part of said case, aheater above said burner consisting of a central tube, upper and lowerheaders connected to said ceny tral tube, inner and outer tubes arrangedin a plurality of concentric series around said header to the other,said tubes being arranged in respectively inner and outer series about acommon axls, and the tubes of the outer series being 1ncl1ned 1n onesense,

while those of the inner are inclined in anv other sense, and cross thespaces between the tubes of the outer series.

11. A heater comprising headers and tubes extending betweensaid headersand connected thereto,l the ends of said tubes passing through holes inthe walls of the headers and being flanged over inside said walls, saidtubes having external shoulders engaging the outer sides of the walls.l

In testimony whereof I have axed my signature, in presence of twowitnesses.

ELMER S. STACK.

Witnesses:

Ur. L. JOHNSON, 1P. W. Pazzrm.

